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Question
Radii of the top and the base of a frustum of a cone are 5 cm and 2 cm respectively. Its height is 9 cm. Find its volume. (π = 3.14)
Solution
`r_1 = 5 cm, r_2 = 2 cm, h = 9 cm`
Area of frustum= `1/3 πh (r_1^2 + r_2^2 + r_1 × r_2)`
= `1/3 × 3.14 × 9 (5^2 + 2^2 + 5 × 2)`
= 3.14 ×3(25 + 4 + 10)
= 3.14 ×3× 39
= 367.38 cm3
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